My 4 year old Great Dane is having this issue . He wakes up from sleep and the poop just starts falling out before he can get outside. He has been to the vet and all of his blood work is fine. He also had an X-ray and he may have a touch of arthritis setting in. The vet put him on prednisolone, which makes him drink a lot so now he is peeing in the house. We are at a loss, not sure what is happening?